Ratchet mechanism



Nov. 26, 1929. A. A. MURSU RATCHET MECHANISM 2 Sheets-Sheet l v Filed 001',- 27. 1927 W'fn sses I INVENTQR. WW/M ATTOkNEY E Nov. 26, 1929. I A. A. MURSU 1,737,323

RATCHET MECHANISM Filed 001',- 27. 1927 2 Sheets-Sheet 2 fir'f/u/r fl Mung INVENTOR.

ATTO'RNEY Patented New. 26, 162% amaze FATE ARTHUR A. I/IURSU, OF FLINT, MICHIGAN BATGI-IET MECHAliIISIVI Application filed. October 27, 1927. Serial No. 229,246.

This invention relates to an improved type of ratchet mechanism designed for use in connection with roll-up tape measures, curtains, screens and articles of a similar nature.

The primary object of the present invention is to provide a ratchet mechanism of improved and simplified construction whereby a spring-controlled rolled-up body'such as a shade, tape measure, or similar article, can be readily adjusted and held in any desired position and may, at the same time, be easily and quickly released for further unwinding or for rewinding.

Other objects and advantages of the present invention will become apparent as the de scription of the same proceeds and the invention will be best understood from a consideration of the following detailed description taken in connection with the accompanying drawings forming a part of the present specification, with the understanding, however, that the invention is not confined to any strict conformity with the showing of the drawings, but may be changed or modified so long as such changes or modifications mark no material departure from the salient features of the invention as expressed in the appended claims.

230 In the drawings:

. Figure 1 shows a plan view of an encased rolled-up tape measure, showing the, ratchet mechanism embodying the present invention, in plan.

Figure 2 shows the ratchet mechanism per se, showing'the relative positions of the parts when the tape measure drum is rotated for unwinding. l V

Figure 3 is view similar toFig. 2 showing 40 the relative positions ofthe parts after stopping the unwinding of the drum to permit the catching of the ratchet.

Figure 4 shows the relative positions of the ratchet parts, in the firstposition to which the drum is moved to release the ratchet to permit rewinding of the tape. v

, Figure 5 shows the relativepositions of the ratchet parts during the counter-clockwise movement of rewinding of the drum.

Figure 6 is a section taken transversely of the complete tape-measure structure, substantially upon the line 66 of Fig. 1.

Figure 7 is a section taken substantially upon the line 7-7 of Fig. 1.

Referring now tothe drawings in detail, wherein like numerals of reference indicate corresponding parts throughout the several vlews, the numeral 1 indicates one-half of a casing. Within the casing there is shown a coiled tape-measure 2, the free end 3 of which passes through the opening 4 and attaches to the button 5 which bears against the casing wall preventingthe end of the tape from being drawn thereinto. 7

While the ratchet structure as shown is associated with a tape measure, and the descriptive matter will be confined to such showing, it is of course to be understood that applicant does not wish to limit himself to the use of the ratchet structure in this manher forthe same is adaptable to a variety of uses and is to be employed wherever found applicable. 7

Within the casing 1 there is mounted the central post 6 about which revolves a drum 7. Within the drum 7 is housed a coiled spring 8, one end of which is secured to the post 6, the other end being secured to the drum in such a manner that when the wound tape 2 is, Withdrawn from the casing and so the drum starts to rotate, the spring 8 will be tightened about the post 6 preparatory to the re-winding of the tape, when desired.

Since the detailedstructure of the controlling spring 8 and the manner in which it is connectedto the adjacent parts form no particular part of the present invention, further description of this structure is thought to be unnecessary.

Mounted in the casing l is a bridge member 9, one end of which is turned downwardly as indicated at 10 and secured tothe bottom wall, of the casing, while the other end extends freely over the drum 7 in the manner shown. The upper end of the post 6 is engaged in the bridge as shown in Figures 6 and 7 and steadied thereby.

The top of the drum 7 is provided about the edge with the pins or posts 11 which ro tate therewith when the tape 2 is withdrawn from the casing, as will be readily understood.

Projecting downwardly from the bridge. 9 at a point between the post 6 and the annular series of pins 11, is a pivot 12 upon which is mounted a trigger device indicated as a whole by the numeral 13..

This trigger member 13 comprises abody portion 14 through which the pin 12 extends,

spring member of substantially U-shaped configuration and indicateda-s a whole by the numeral 18. This spring 18 has the post 6 passed centrally therethrough with the free ends of the legs 19 and 20arranged on opposite sides of the trigger 13.

Secured to one side edge of the bridge member .9 adjacent the leg 20 of the spring 18, is a coiled spring 21, one end of which engages in a notch 22 on the top edge of the spring leg 20 to normally urge the spring 18 towards the trigger 13. From the opposite side of the post 6, the bridge 9 .carries a fiat spring 23 one end of which is secured to the bridge while the other end thereof bears against the leg 19 of the spring 18 normally urging the spring in a path at right angles to the path in which the spring is :urged to move under the pressure of the spring memher 21. V

The ends .of the legs 19 and 20 of the spring 18 are in alinement, as shown, and the leg. 19 terminates in the hook 23 which, under certain operating conditions of the ratchet, en gages over the edge of the depending finger 24 which is struck from'the adjacent side edge of the bridge member 9.

From the foregoing, it will be readily understood that the spring member 18 is free to move in a line parallel with the line upon which the post 6 and pin 12 lie and at the 7 same time can move at right angles to this line; I

The tape 2 may be retained in position in the .case 1 in any desired manner, for example, by the use of the split spring ring 25 which is encased in the body land which has the; inwardly extending portions or sections 26 tooverlie the edge of the tape to maintain it in position. 7

The operation of the ratchet structure just described is as follows. Starting withthe tape in the Wound-upposition as shown in Fig. 1, the spring 18 will be in a position where the hook 23 is engaged over the head of the rotating pins 11.

the depending finger 24, the trigger member being swung to the position where the free end of the spring leg 20 will bear against the outer side of the catch 17. The withdrawing of the tape 2 will cause the trigger 13 to swing to the position shown in Fig. 2 due to theengagement of the end of the arm 15 with The positionof the spring 18 remains unchanged but it will be noted that the trigger catch has swung to a position forwardly of the end of'the spring arm 20 so that the end of this arm now lies in a position to be engaged by the catch upon the return swing-of the trigger.

When the tape has been withdrawn to the desired position and released, thespring member 8 willcausea reverse rotation ofthe drum .7 thereby causing one of the 'pins 11 to engage the arm 15 of the trigger and swing the same back to its initial position. The free end of the leg 2.0 of the spring 18 is then engaged by the catch "17 and moves longitudinally against the action of the spring 21. This disengages the catch 23 from the finger 24; allowing the leg 19 to be forced inwardly by the spring 23. As will be readily seen, the further swinging of the trigger 13 will be prevented by the leg 20 and the rotation of the drum stopped. This second described position is clearly shown in Fig. .3. i

Referring now to Fig. i of the drawing, it will be seen that when it is desired to rewind the tape, the same must first be pulled slightly outwardly to cause the clockwise rotation of the drum 7 so that one of the pins 11 will again engage the arm 15 to swing the trigger to the position shown. This releases the leg 20 of the spring 18 allowing it to fly outwardly out of the path of thecatch 17 Release of the tape now permits the counterclockwise movementof the drum 7 to wind the tape thereon causing the trigger to be again forced back, at which time the catch 17 will swing behind the spring leg 20 and the finger 16 will then be brought to bear against the leg 19 and push thesame outwardly against the tension of the spring 23' until the hook 23 is in .a position to be forced forwardly bythespring 21 for engagement over the depending finger 24. This last position of the U-shapedsprmg 18, while the tape is being re-wound on the drum 7 and before the spring 21 has acted to ed trigger member for engagement with said spring engaging members carried by said rotary member to engage said trigger, springs for shifting said main spring in two right-angularly related lines for the operation of the ratchet.

2. A ratchet mechanism of the character described, a rotary spring-controlled member, an annular series of contact members carried by said rotary member and arranged about the pivotal center thereof, a substantially U-shaped spring overlying the rotary member and a trigger arranged between the ends of the legs of said spring, means carried by said trigger for engagement with said pins, means for setting up a latching engagement between the trigger and the end of one leg of said spring, and means for causing said spring to shift both longitudinally and transversely of its length.

3. A ratchet mechanism of the character described, comprising. a spring-controlled rotary member, an annular series of pins car-- ried by said member about the povital center- I thereof, a substantially U-shaped spring member overlying said rotary member, oneof the legs of said spring being formed to provide a hook, a pivotally mounted trigger member arranged between the ends of said spring legs, an arm carried by said triggerfor engagement with said pins, a catch member carried by said trigger designed to engage the end of the other leg of said spring, a"

trip finger carried by the trigger designed to engage the the hook at the end of the spring ARTHUR A. MURSU. 4 

